Electric water heater



Jnf 79 w35 s. H. WINN Z@ ELECTRIC WATER HEATER Filed Nov. 20, 1953 MMM I yic iIr"

E? 7 ATTORNEY Patented Jan. 7, 193@ UNi'iiB STAT.iiSiA i'iei'i'EN'f OFFICE ELECTRIC WATER HEATER Sperry H. Winn, Seattle, Wash.

Application November 20, i933, Serial No. 698,825

12 Claims.

My invention relates to electric water heaters of the type in which the water is brought into direct contact with the electric heating element and the general object of my invention is to provide an 5 electric water heater oi this type which is simple and inexpensive in construction and highly eiiicient in operation.

Another object of the invention is to provide,

an electric heater in which all of the insulating parts are made oi phenolitic condensation product, one suitable form of which may be the product commonly known by the trade naine of Bakelitej which has high insulating qualities, is substantially non-absorbent, is durable in use and is highly resistant to breakage.

Another object of the invention is to provide an electric water heater of this nature in which the bottom of the heating chamber is formed of a phenolitic condensation product base plate and 20 in which the terminal posts enter the water heating chamber through this phenolitic condensation product base plate and are thus eiectively insulated against grounding or short circuiting, and to further provide eiiicient means for clamping and holding said phenolitic condensation product base plate member in such a manner that it forms a liquid tight connection with the housing and at the same time is easily removable for the purpose of replacement and repair.

Another object is to provide simple and eicient assembly means for the heating elements and to provide eicient means for insulating said heating elements against leakage of current, short circuiting and grounding.

Other and more specic objects of the invention will be apparent from the following description taken in connection with the accompanying drawing.

In the drawing Figure l is a View in vertical section of an electric water heater constructed in accordance with my invention.

Fig. 2 is a cross section of the same substantially on broken line 2 2 of Fig. l.

Fig. 3 is a detached View in elevation of the heating unit assembly.

Fig. 4 is a detached elevation of a terminal post embodied in the invention.

Fig. 5 is a detached View partly in elevation and partly in cross section showing a heating unit base oi insulating material and showing a tubular lining or" insulating material positioned on said base, parts of said tubular lining being broken away.

Fig. 6 is a top plan view of the heating unit base.

Fig. 7 is an elevation on a reduced scale illusile trating an installation of my electric water heater in connection with an ordinary domestic hot water tank.

Referring to the drawing, the numeral l designates a tubular housing constructed with an open 5 bottom end and provided around this bottom end with an external thread il for the reception of an internally threaded portion i2 of a housing base i3. An inwardly directed clamping flange it is provided in the housing base I3. An inio ternally threaded tubular boss le is provided on one side ci the housing iii adjacent the bottom end thereof for connection with a Water inlet pipe l5. An annular water circulation space I6 is provided in the lower end portion of the housing l 0 in regis- 15 tration with the tubular boss ifi. This annular water circulation space is formed by providing a section of enlarged diameter within the housing said enlarged section terminating short of the bottom end of the housing. The upper end of the housing lil is partially closed and is provided with an internally threaded axial tubular boss Il for connection with a Water outlet pipe I8. The exterior of the boss il is preferably hexagonal whereby a wrench may be placed thereon.

A phenolitic condensation product tube 20 of slightly smaller diameter than the interior of the housing it is disposed to t snugly within said housing and is freely removable and insertable in the housing when the housing base I3 is removed. This tube forms an insulating lining which ts the housing snugly except at the location ci the enlarged water circulation space I6. ./-it the location of this water circulation space i6 the lining tube 2t is provided with a plurality of openings 9 in the walls thereof through which the water is free to enter in evenly distributed relation around the liner tube 26.

The electric heating unit assembly comprises a circular integral base plate, of insulating material, as phenolitic condensation product, to which the heating elements and terminal posts are secured. This base plate has an upwardly extending boss portion 2i and a downwardly extending boss portion 22 and an annular flange 23. The upwardly extending boss portion 2| has two larger recesses 213 extending from the top downwardly and these recesses 24 are intersected by two smaller holes 25 which extend from the bottom of the lower boss portion 22 upwardly and are centrally positioned as respects the recesses 2t.

The holes in the base plate formed by recesses 2d and holes 25 are adapted to receive binding posts 25. These binding posts 26 are preferably each provided at the upper end with an integral annular "-head portion 2l and an eye portion 2S. The binding posts are inserted in the base plate with the heads 2l positioned in the recesses il the posts 26 extending down through the holes 25. Packing washers Si are provided between the heads 2l of the binding posts and the bottoms of the recesses 2li to prevent leakage around the binding posts 2d. On the lower end of each binding post 26 I preferably provide tightening means which maybe in the nature of a washer 3, a nut 33, and a nut 3d. Another washer and nit 3% are provided for holding the wires 52 through which current is supplied.

Two heating coils El and 33 are electrically connected with the respective binding posts 2E, preferably by screws lll which screw into threaded holes in the eye members 2d. The two heating coils 3i and 38 are preferably formed of a single piece of high resistance wire and are electrically connected with each other at their upper ends as by a straight wire section fil-i whereby said two coils will be electrically connectedin series. The heating coils il and iid are housed within tubes #i2 and i3 respectively, of insulating material, as phenolitic condensation product. The lower ends of these tubes l2 and 3 are positioned within the recesses dii whereby the tubes are held in an upright position, as shown in Figs. l and 2. The upper ends of the tubes and. 3 are slotted longitudinally from the top down for a short distance as shown at is and the straight section il spacermember l5 will be supported by the element wire section iii. The split l5 makes it possible to slip the spacer S5 over the wire section il and said split l5 is preferably narrow enough .so that the spacer' will not drop oiiE of the wire il after it has been placed thereon.V The heating element coils 3l and 3B, as originally wound, are of shorter length than the insulation tubes 42 and i3 and said coils ar-e made of resilient wire whereby the said heating coils act as tension springs to urge the tubes and i3 down in the recesses Ztl, thus helping to hold said tubes and i3 in upright position. lThis also leaves the tubes 42 and 5.13 loosely supported so that they may be readily lifted up to aiiord access to the screws te. This construction is important, as it facilitates speed and ease of assembly of the device and provides a construction which can not be damaged by expansion and contraction. The tubes 132 and i3 have holes il in their walls adjacent their lower ends and other holes i8 in their walls at spaced intervals above the holes il whereby the water enter into the tubes pass upwardly in the tubes in direct Contact with the heating coils. It will be noted that the lowermost holes il are positioned at a substantial distance above the top side oi the base plat-e member 2l so that if any sediment collects in the bottom of the heater it will not enter the holes il and there will be substantially no danger or" sediment short circuiting the heating coil or iorrning a short circuit between the two terminal posts. By providing holes di? at intervals throughout the length of the tubes l2 l make it possible for water to enter these tubes at various points and thereby secure a higher eftlciency, avoid overheating small portions or the water, heat the entire body of water more evenly and safeguard the heating coils from being overheated. Ii water could not enter at a plurality of diilerent elevations then all of the water entering through the 5 bottom holes ill would have Vto traverse the entire length oi the tubes without being mixed with any cooler water and might be heated much hotter than is necessary and the heating elements might be subjected to a higher temperature than 10 is required for satisfactory operation.

The heating coils 3l' and 38 together with the base and terminal posts and tubes i2 and form a unitary assembly which is insertable into and removable from the housing as a unit when the l5 housing base i3 is removed.' When the heater is assembled, as shown in Fig. l, the circular flange portion 23 oi the heating unit base is securely clamped between the bottom end of the housing lil and an internal flange i8 in the housing base 20 i3. A gasket 29 which rests on top of the iiange i9 and is engaged by the lower end oi the housing lil forms a water tight seal and prevents leakage between the insulating base plate and the lower end of the housing. 25

The upper portion lll of the housing base i3 being of hexagonal shape externally, may readily be engaged by a wrench for the purpose oi screwing the base onto or ofi" of the housing. This makes is possible to easily dis-assemble the heater 30 without danger of breaking the housing even though the threads l l and l2 have not been relatively moved for a long period of time.

In the installation of this water heater in connection with an ordinary domestic hot water 35 tank 5u the heater is preierably positioned so that the lower end of the water circulation chamber in the heater is level with or below the bottom end of the hot water tank as shown in Fig. 7. The water inlet pipe l5 at the lower end of the 40 water heater is connected with the lower portion of the hot water tank and the water outlet pipe i8 from the upper end of the water heater is connected with the upper portion of the hot water tank. When thus installed, cold water which is 45 delivered through a pipe 5l to the lower portion of the hot water tank 5E! will flow into the heater through the pipe i8 and will then pass upwardly through the heater and be heated and will then be delivered by the pipe i8 into the top end of 5o the hot water tank from which it may be drawn oi in the usual manner.

In passing upwardly through the water heater a portion of the water cornes into direct contact with the heating elements in itsupward travel through the tubes i2 and 43 and the entire bddy of water is heated suiciently for domestic purposes without being overheated. The efficiency of the heater is high in proportion to the amount of current consumed due to the direct contact of (30 the water with the heating elements and the electrical losses in the heater are low due to the heating elements and terminal posts being very thoroughly insulated from the metal housing by the tubes d2 and i3 and the insulating lining 26 65 and the insulating base plate.

Circuit wires 52 which enter the housing base i3 through a fitting 53 may connect the terminal posts 26 with any suitable source of supply o electric current. 70

The foregoing description and accompanying drawing clearly disclose a preferred embodiment of my invention but it will be understood that this disclosure is merely illustrative and that such changes in the invention may be made as are fairly within the scope and spirit of the following claims.

I claim:

l. In an electricv water heater of the class described; a tubular metal housing; a tubular phenolitic condensation product lining in said housing; a phenolitic condensation product base in said housing; two terminal posts extending through said base and relatively insulated by said base, electric water heating coils electrically connected between said terminal posts and phenolitic condensation product tubes enclosing said coils said phenolitic condensation product tubes having openings at 'intervals in the walls thereof.

2. In -an electric water heater; a tubular metal housing; a phenolitic condensation product base having a liquid tight connection with the bottom of said housing; two terminal posts extending through said phenolitic condensation product base, two water heating coils in said housing connected in series between said terminal posts and extending upwardly from said base; a phenolitic condensation product tube enclosing each of said heating coils; water circulation openings in the walls of said tubes; a tubular phenolitic condensation product lining within said housing; and liquid circulating conduit means connected with said housing.

3. In an electric water heater; a tubular metal housing; a base of insulating material having a liquid tight connection with the bottom of said housing; two terminal posts extending through said base, two water heating coils in said housing connected in series between said terminal posts and extending upwardly from said base; a tube of insulating material enclosing each of said heating coils; water circulation openings in the walls or" said tubes; a tubular lining of insulating material within said housing; and liquid circulating conduit means connected with said housing.

4. In an electric water heater; a tubular metal housing; a base of insulating material having a liquid tight connection with the bottom of said housing; two terminal posts extending through said base, two water heating coils in said housing connected in series between said terminal posts and extending upwardly from said base; two tubes of insulating material enclosing the respective coils and fitting over the upper ends of said terminal posts; each tube having a water circulation opening positioned a substantial distance above the top end of the enclosed terminal post; and liquid circulation means connected with said housing. l

5. In an electric water heater; a tubular metal housing; a base of insulating material having a liquid tight connection with the bottom portion of said housing, said base having two recesses formed in the top side thereof; two terminal posts extending upwardly through said base and having upper end portions positioned in said recesses; two upright heating coils within said housing electrically connected in series between said terminal posts, two tubes of insulating material enclosing the respective heating coils and having their lower ends positioned in said recesses and enclosing the upper ends of said terminal posts, said tubes having water circulation openings in the walls thereof; and liquid circulation conduit means connected with said housing.

6. In an electric water heater; a tubular metal housing; a base of insulating material having a liquid tight connection with the bottom portion of said housing, said base having two recesses formed in the top side thereof two terminal posts extending upwardly through said base and hav ing upper end portions positioned in said recesses; two upright heating coils within said housing elec- 5 trically connected in series between said terminal posts, two tubes of insulating material enclosing the respective heating coils and having their lower ends positioned in said recesses and enclosing the upper ends of said terminal posts whereby said tubes are supported in upright position and said terminal posts are protected from sediment deposits, said tubes having water circulation openings provided in the walls thereof above said terminal posts; a tubular lining of insulating material within said housing surrounding said tubes and said heating coils; and liquid circulation conduit means connected with said housing.

7. In a direct contact electric water heater; a housing having liquid circulation means conf nected therewith; and an electric water heating unit of the direct contact type in said housing, said electric water heating unit embodying a base having two recesses in the upper side there- 2:3 of, two perforated tubes of insulating material having their lower ends positioned in said recesses whereby they are loosely supported in substantially parallel upright relation, two terminal posts extending upwardly through the base and 3H into the bottom ends of said tubes, two helical wire heating coils in said tubes, said coils being electrically connected with each other and mechanically connected with said tubes at their upper ends and beingv electrically and mechanically connected with said terminal posts at their lower ends and being under tension whereby said tubes are yieldingly held in engagement with said base.

8. In a direct contact electric water heater; a housing having liquid circulation means connected therewith; and an electric water heating unit of the direct contact type in said housing, said electric water heating unit embodying a base having two recesses in the upper side thereof, two tubes of insulating material having their lower ends positioned in said recesses whereby they are loosely supported in substantially paryallel upright relation said tubes having water circulation openings therein, two terminal posts extending upwardly through the base and into the bottom ends of said tubes, two resilient helical wire heating coils in said tubes the lower ends of said coils being electrically and mechanically connected with said terminal posts, notches in the upper ends of said tubes, a spacer between the upper ends of said tubes and a section of conductor wire extending crosswise between said tubes through said notches and said spacer, said heating coils being under tension whereby said tubes are yieldingly held in engagement with said base.

9. In an electric water heater; a tubular housing having a portion of enlarged internal diameter adjacent the lower end, a tubular lining o5 of insulating material of substantially the same length and slightly smaller diameter than said housing disposed ip said housing and leaving an annular water circulation space around said lining at the location of the enlarged internal portion of said housing, said lining having openings in the walls thereof in registration with the enlarged internal portion of said housing; water inlet means communicating with the enlarged internal portion of said housing; water outlet ing, said lining having holes in its walls adjacent Vthe lower end; fluid inlet conduit means connected with the lower end portion of said housing; fluid outlet conduit means connected with the upper end portion of said housing; an insulating base having an annular ange portion adapted to be clamped between the bottom end of said housing and the flange of said housing base, two terminal posts extending through said base; two heating coils electrically connected with said terminal posts; and tubes of insulating material enclosing said heating coils, said tubes having openings at intervals in the walls thereof.

l1. In an electric water heater of the class described; a tubular metal housing having a portion of enlarged internal diameter adjacent the lower end; external threads on the bottom end of said housing; a housing base having internal threads adapted to screw onto the bottom end of said housing; an internal annular iiange said housing base; a tubular cylindrical phenolitic condensation product lining adapted to nt snugly within said housing, said lining having holes therein at the location of the enlarged internal portion of said housing; fluid inlet conduit means connected with the lower end portion of said housing; iiuid outlet conduit means connected with the upper end portion of said housing; a phenolitic condensation product base having an annular iiange portion adapted to be clamped between the bottom end of said housing and the flange of said housing base, two terminal posts extending through said base; two heating coils in said housing electrically connected in series with said terminal posts and phenolitic condensation product tubes enclosing said heating coils, said phenolitic condensation product tubes having openings at intervals in the walls thereof.

l2. In an electric water heater; a tubular metal housing having an open bottom end; a housing base adapted to screw onto the bottom end of said housing; an internal annular flange in said housing base; a base plate oi insulating material closing the bottom end of said housing, said base plate having a centrally positioned boss of smaller diameter than said housing projecting upwardly into said housing and leaving an annular space between said boss and the housing wall and said base plate having a iiange portion clamped between the bottom end of the housing and the internal flange of the housing base; a tubular lining of insulating material disposed within said housing with its bottom end positioned in the annular space formed between said boss and said housing, said lining having openings in the walls thereof adjacent the lower end; electric water heating elements mounted on said base plate and positioned in said housing; and water circulation means connected with said housing.

SPERRY H. WINN. 

